diff --git a/src/OpenThreads/pthreads/PThread.cpp b/src/OpenThreads/pthreads/PThread.cpp
index 3bec4ffbc..965514a23 100644
--- a/src/OpenThreads/pthreads/PThread.cpp
+++ b/src/OpenThreads/pthreads/PThread.cpp
@@ -638,6 +638,12 @@ bool Thread::isRunning()
 //
 int Thread::start() {
 
+    PThreadPrivateData *pd = static_cast<PThreadPrivateData *> (_prvData);
+    if (pd->isRunning())
+    {
+        return 0;
+    }
+
     int status;
     pthread_attr_t thread_attr;
 
@@ -647,8 +653,6 @@ int Thread::start() {
         return status;
     }
 
-    PThreadPrivateData *pd = static_cast<PThreadPrivateData *> (_prvData);
-
     //-------------------------------------------------------------------------
     // Set the stack size if requested, but not less than a platform reasonable
     // value.
diff --git a/src/OpenThreads/win32/Win32Thread.cpp b/src/OpenThreads/win32/Win32Thread.cpp
index 9ade67eb7..3444b6b2b 100644
--- a/src/OpenThreads/win32/Win32Thread.cpp
+++ b/src/OpenThreads/win32/Win32Thread.cpp
@@ -336,6 +336,11 @@ bool Thread::isRunning() {
 int Thread::start() {
 
     Win32ThreadPrivateData *pd = static_cast<Win32ThreadPrivateData *> (_prvData);
+    if (pd->isRunning)
+    {
+        return 0;
+    }
+
     //-------------------------------------------------------------------------
     // Prohibit the stack size from being changed.
     // (bb 5/13/2005) it actually doesn't matter.